Travis, Gerardo, Jordan

During the closing of GV6 back in May, we noticed that there was some blow-by in the pneumatic system when trying to hard close the valve, see alog 90093. 

We were able to hard close the valve eventually but as preventative maintenance we wanted to replace the air cylinder seals, similar to GV7.

Prior to disassembly we measured the locations of the reed switches from the top surface of the bottom plate to the bottom surface of the reed switches:

Bottom Switch: 1 1/8"

Top Switch: 49 1/4"

We then disassembled the air cylinder and replaced the seals following procedure/notes collected during the GV7 repair. During cleaning of the old grease on the piston head, we noticed there were two burrs on the top of the piston, we did not notice any damage to the inside of the cylinder, but as a precaution we used a small flat file to remove the burrs. We also chased the threads on the four threaded rods with a die to aid with reinstallation. After cleaning and inspection of the cylinder tube, we found no issues or damage so we decided to continue to use that cylinder and keep the new one as a spare.

No other issues encountered, we removed the old seals, cleaned the grooves, added copious amounts of the supplied grease to the o-rings, seals and the inside of the air cylinder, and then re-assembled the cylinder tube. Pictures posted below and a final procedure is in progress and will be posted to the DCC.

We did not get a chance to cycle the valve after the seal replacement, so we will continue tomorrow with cycling the valve.